(a) Field of the Invention
The present invention relates to a shift/select lever unit for dual-mode automatic transmissions in which both automatic and manual shifting capabilities are provided.
(b) Description of the Related Art
A relatively recent development in the automatic transmission allows for both automatic and manual shifting. That is, the transmission has the conventional automatic modes, but enables manual control in the drive D range so that the driver can have more control over the vehicle. Such an arrangement is more often found in sports vehicles.
A select lever unit used in the dual-mode automatic transmission generally includes a select lever operated by the user to change shift modes and ranges; a cable bracket connected to a shift cable and which is indexed with the select lever when the select lever is in an automatic mode to operate a manual valve of the transmission; and a connecting lever member formed on the select lever to enable the select lever and the cable bracket to move together according to changes in the automatic mode, the cable bracket being provided with a lever connecting hole corresponding to the connecting lever member.
An indentation is provided on an upper portion of the lever connecting hole for insertion of the connecting lever member to fix the connecting lever member's relative motion with respect to the cable bracket along certain directions when the select lever is in the automatic mode, thereby forming an automatic mode range. Also, a bottom portion of the lever connecting hole is realized through a manual mode range having a predetermined width to enable freer movement of the connecting lever member during plus and minus shifting in the case where the select lever is in the automatic shift mode.
Accordingly, the operation of the select lever unit is such that the connecting lever member selectively moves in ranges in the lever connecting hole according to mode changes of the select lever, thereby either transmitting or discontinuing operational force of the select lever on the shift cable. When the select lever is in the automatic mode, the connecting lever member is inserted in the automatic mode range of the lever connecting hole such that the select lever and the cable bracket integrally move together, and if the select lever is converted to a manual mode, the connecting lever member is removed from the automatic mode range of the lever connecting hole such that the select lever and the cable bracket no longer integrally move together.
In the manual mode, the cable bracket must be fixed in the drive range. This is realized by the action of a detent spring formed on one side of the cable bracket and a detent plate formed on a main frame. However, the degree to which the cable bracket is secured in the drive range is dependent upon the operation of the elastic force of the detent spring on a groove of the detent plate. As a result, shaking or vibrations of the vehicle body can compromise the anchoring of the cable bracket in the drive range, possibly resulting in safety problems.